[parisc-linux] O_DIRECT on devices

[Patrick Caulfield]

I'm currently working on LVM2 and we want to use O_DIRECT to write the metadata
from userspace. so I open a partition with O_DIRECT and try to read/write the
data from an aligned buffer.

This works fine on Alpha & Intel but seems very unreliable on parisc for some
reason. Sometimes it works, sometimes it oopses "do_page_fault() pid=2120
command='lvm' type=15 address=0x00000001" and sometimes I just get back the
wrong information (at least LVM thinks its wrong I haven't check in detail just
what is up with it).

I haven't tried writing yet - I'd rather not think what might happen to my disk
just ATM :)

This is a C110 with 256meg of memory running 2.4.18-pa46

patrick